A variety of display apparatus such as a cathode ray tube (CRT), a liquid crystal display (LCD) device using electric field optical effect, a plasma display panel (PDP) using gas discharge, and an electro-luminescence display (ELD) using electric field light emission effect are well known. Among the displays, the LCD device has been actively researched and developed.
The LCD device has been applied to various fields taking advantage of its features of light weight, small thickness, and low power consumption while overcoming disadvantages of the CRT.
The LCD device is a passive-type (non-emissive type) display apparatus that displays an image by adjusting an amount of external light. Therefore, an external light source such as a backlight unit is necessary for the LCD device.